Cortical Engagement Metrics During Reactive Balance Are Associated With Distinct Aspects of Balance Behavior in Older Adults

• Type of Material: Article
• Authors: Jacqueline A Palmer, Emory University; Aiden M Payne, Emory University; Lena Ting, Emory University; Michael Borich, Emory University
• Language: English
• Date: 2021-07-14
• Publisher: FRONTIERS MEDIA SA
• Publication Version: Final Published Version
• Copyright Statement: © 2021 Palmer, Payne, Ting and Borich.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.3389/fnagi.2021.684743
• Title of Journal or Parent Work: FRONTIERS IN AGING NEUROSCIENCE
• Volume: 13
• Start Page: 684743
• End Page: 684743
• Grant/Funding Information: This work was supported by postdoctoral fellowship awards from the American Heart Association (AHA00035638) and the Eunice Kennedy Shriver National Institute of Child Health & Human Development of the National Institutes of Health (F32HD096816) to JP, (K12HD055931) to MB, and (5T90DA032466, 1P50NS098685, R01 HD46922) to LT, and a grant from the National Science Foundation (1137229) to LT.
• Keywords: DYNAMICS; RECOVERY; aging- old age - seniors; sensorimotor system; posture; beta activity; EVENT-RELATED DESYNCHRONIZATION; response inhibition; Neurosciences; functional connectivity; Science & Technology; Life Sciences & Biomedicine; OSCILLATORY ACTIVITY; Geriatrics & Gerontology; PERTURBATION; prefrontal cortex (PFC); BRAIN; INTRACORTICAL INHIBITION; dual task (DT); Neurosciences & Neurology; AGE-RELATED-CHANGES; POSTURAL STABILITY; MOTOR-PERFORMANCE
• Research Categories: Health Sciences, Rehabilitation and Therapy; Engineering, Biomedical

Abstract

Heightened reliance on the cerebral cortex for postural stability with aging is well-known, yet the cortical mechanisms for balance control, particularly in relation to balance function, remain unclear. Here we aimed to investigate motor cortical activity in relation to the level of balance challenge presented during reactive balance recovery and identify circuit-specific interactions between motor cortex and prefrontal or somatosensory regions in relation to metrics of balance function that predict fall risk. Using electroencephalography, we assessed motor cortical beta power, and beta coherence during balance reactions to perturbations in older adults. We found that individuals with greater motor cortical beta power evoked following standing balance perturbations demonstrated lower general clinical balance function. Individual older adults demonstrated a wide range of cortical responses during balance reactions at the same perturbation magnitude, showing no group-level change in prefrontal- or somatosensory-motor coherence in response to perturbations. However, older adults with the highest prefrontal-motor coherence during the post-perturbation, but not pre-perturbation, period showed greater cognitive dual-task interference (DTI) and elicited stepping reactions at lower perturbation magnitudes. Our results support motor cortical beta activity as a potential biomarker for individual level of balance challenge and implicate prefrontal-motor cortical networks in distinct aspects of balance control involving response inhibition of reactive stepping in older adults. Cortical network activity during balance may provide a neural target for precision-medicine efforts aimed at fall prevention with aging.